The present invention relates to an identification mark comprising an optically and an electronically readable marking. The electronic marking comprises an (acoustic/electro)magnetic marking, having a soft magnetic layer, and the optical marking comprises a structure provided with a relief.
An identification mark of this type is disclosed in European Patent Application 0 673 853. This publication describes a security marking. A security marking is a marking which reacts to an acoustic, electrical or (electro)magnetic signal which if it is not deactivated, for example taken past an antenna in a shop without being paid for, can cause a signal to be triggered. A security marking of this type is provided with screening that can be deactivated. If it is handled correctly, that is to say deactivated, the effect of the soft magnetic layer used in the security marking can be negated by deactivating it. The optical marking described in European Application 0 673 853 comprises a hologram. Purchasers can see from this hologram whether a product is a genuine brand product or an imitation. According to what is described in the said European Application, the hologram is fixed to the authenticity marking by means of an adhesive. This joining technique, that is to say the use of adhesive, is relatively complex in the case of large-scale production and increases the cost price, but, on the other hand is attractive to imitators. After all, ever increasing numbers of forged holograms are coming onto the market, whilst authenticity markings are likewise being forged.
The aim of the present invention is to provide an improved identification mark which, on the one hand, is less expensive and can be produced more accurately in large runs but, on the other hand, is more difficult to copy.
This aim is achieved with an identification mark as described above, and which comprises an authenticity marking provided in the electronically readable marking. The soft magnetic layer has a thickness of less than 1 xcexcm, and an additional metallic layer, which contains the optically readable marking. According to the invention, the hologram or other optical marking is joined to the (acoustic/electro)magnetic marking during the production process itself. By this means an efficient and accurate production process can be provided whilst copying is made more difficult. After all, the identification mark obtained according to the invention no longer consists of the simple combination of a hologram and authenticity marking. In contrast to the European Application 0 673 853 described above, there is no adhesive layer between the hologram component and the (acoustic/electro)magnetic component.
It is possible to deposit the additional metallic layer directly on the soft magnetic layer. According to another embodiment, it is possible to insert an intermediate layer, such as a carrier layer consisting of PET, OPP or PVC. The same applies with regard to the optical marking. The latter can either be incorporated directly in the additional metallic layer, but also in a coating applied thereon. The optical marking is preferably a hologram. Holograms are also understood to include kinegrams, pixelgrams, kineforms and the like. These can be either two-dimensional or three-dimensional. Holograms are also understood to include xe2x80x98Optical Variable Devicesxe2x80x99 (xe2x80x98OVDxe2x80x99), that is to say devices which are optically readable, for example with the aid of a scanner. Pixel comparison is likewise possible. A hologram can be applied in any way known in the sate of the art. Embossing is one possibility and this is used in particular if the hologram is applied in the additional metallic layer. This additional metallic layer can comprise any material known in the art and according to a preferred embodiment consists of aluminium.
The (acoustic/electro)magnetic marking described above can be either an authenticity marking or a security marking. The hologram described above is an authenticity marking. The combination described above of a soft magnetic layer and a (hard) magnetic layer that can be deactivated is a security marking. However, it is possible for the marking according to the invention to be implemented solely as an authenticity marking, that is to say for only a soft magnetic layer to be present which cannot be deactivated in any way whatsoever. So as not to trip existing security devices in such a case, it can be necessary to reduce the effectiveness of such a soft magnetic layer, for example by reducing the thickness thereof. Whereas in the prior art and in the invention the layer thickness of a soft magnetic layer for a security marking is approximately 1 xcexcm, when said marking is used as an authenticity marking said layer thickness will be considerably less than 1 xcexcm and in a preferred embodiment less than 0.5 xcexcm. With the aid of such an (electro)magnetic authenticity marking it is possible to detect markings which are inside packaging, that is to say in situations where the hologram is not visible, with the aid of relatively simple equipment. Moreover, it is possible to give different products different (electro)magnetic characteristics which are characteristic of the products concerned. For instance, the composition of the soft magnetic layer can consist of various quantities and combinations of soft ferrous and non-ferrous metals, such as copper, cobalt, silver and gold. Likewise, a difference in relief, coarser or finer, in the metallic layer and/or the magnetic layer can be produced by using different embossing (hologram, etc.), by means of which the nature of the (electro)magnetic signal is influenced.
By means of different combinations it is possible to recognise and distinguish different types of products. It is possible to recognise different products from a distance of, for example, 5 cm using relatively simple equipment.
As indicated above, the identification mark can be implemented either as a security marking or as an authenticity marking. It is possible to attach the identification mark according to the invention to packaging, but also to attach it to documents to guarantee the authenticity thereof. The fixing technique can be any technique known in the state of the art, such as sticking. According to an advantageous embodiment of the invention, said fixing technique also comprises the hot stamp technique. With the latter technique fusion takes place between the material to which the identification mark has been applied and that layer of the identification mark which adjoins said material. As a result it is not possible to remove the identification mark without damaging the packaging and/or document concerned. This offers appreciable security.
It will be understood that the abovementioned layers of the identification mark are only those layers which are essential to the invention. Depending on the application and the production method, numerous further layers can be present, as will also be seen from the illustrative embodiments described with reference to the drawings.
The deposition technique described above for the additional metallic layer, such as an aluminium layer, can comprise any deposition technique known in the state of the art. In this context consideration is given to the vacuum deposition technique, but also to sputtering techniques.
It is possible to make the identification mark according to the invention in any shape. For instance, for use on a compact disc the identification mark could be produced in the form of a ring which extends around the central opening. This ring can then be applied either with the aid of an adhesive auxiliary layer or by using the hot stamp technique described above. In the case of use on a compact disc, the identification mark can be either an authenticity marking or a security marking.
The present invention also relates to a method for the production of the identification mark described above. With this method the optical marking and the (acoustic/electro)magnetic marking are produced in an unbroken sequence of steps as a single identification mark. That is to say, preferably, after provision of a layer of material having soft magnetic properties, a further metallic layer is applied thereon with the aid of a deposition technique, in which further layer the hologram is then produced. As indicated above, an auxiliary layer, for example composed of plastic material, can have been applied between the soft magnetic layer and the additional layer, which preferably consists of aluminium. Moreover, the additional layer can have been provided with a (plastic) coating in which the hologram is then produced. That is to say, in contrast to the prior art, it is not the case that, on the one hand, an (acoustic/electro)magnetic marking and optical marking are provided in two completely separate steps and these two layers are then joined to one another in a third step, but the hologram or any other optical identification mark is produced in a step integrated in the process in a layer which has already been joined to the soft magnetic layer.